You know there are countless reasons to exercise: Working out supports your overall health by building muscle, boosting cardiovascular fitness, and improving mental wellbeing. Among these benefits, you may have also heard that exercise increases your metabolism. 

There is some truth to this, experts say. But metabolism is complex, and its connection with exercise isn’t always so clear cut. What’s more, working out intensely isn’t necessarily going to result in dramatic, long-term metabolism changes for everyone.

“While there are some things you can do to influence your metabolism, like staying active and building muscle, it isn’t entirely in your control,” says Brent Smith, MD, a family physician and board member of the American Academy of Family Physicians (AAFP).

Read on to learn more about how exercise impacts metabolism, plus which workouts may especially give it a boost.

What Is Metabolism?

Metabolism refers to how our body turns the things we eat and drink into energy to support our bodily functions. This process is commonly referred to as “burning calories.” 

But contrary to what you might have heard before, metabolism isn’t just about weight management. In fact, the metabolic process is absolutely essential to our overall health. “It’s all of the chemical processes and reactions that occur within our living body in order to maintain life,” says Courtney Pelitera, RDN, a registered dietitian at Top Nutrition Coaching specializing in sports nutrition and wellness nutrition.  

Specifically, metabolism allows the body to eliminate waste, control body temperature, contract muscles, and much more. “It’s always working in the background, powering everything from your heartbeat to your breathing,” Dr. Smith explains.

Metabolism is self-regulating, and works a little faster or slower at different times of day or during various life stages through a process known as metabolic rate. “Your specific metabolic rate is unique,” Dr. Smith says. “Some people can have a fast or slower metabolic rate that isn’t tied to body shape or size.” A “fast” metabolism means your body is burning more calories at rest; a “slow” one requires fewer calories, the Cleveland Clinic notes.

Metabolic rate can be influenced by other factors, too, including how hungry you are, if you’re pregnant or breastfeeding, and if you’re currently exercising, to give a few examples. But this rate isn’t a complete indicator of your health, Dr. Smith stresses. “You’re not defined by the speed of your metabolism.”

Does Exercise Increase Metabolism?

So does working out more actually result in a higher-than-typical metabolic rate? “It does, to a degree,” Dr. Smith says. This is thought to happen through a few different processes:

1. Exercise Uses More Energy

When you’re doing cardio workouts such as running, indoor cycling, or swimming, your heart rate goes up, you’re breathing more heavily, and you’re exhausting those hard-working muscles. “These processes burn calories at a higher rate than when our body is at rest, because it takes more energy to do these things,” Dr. Smith says. 

Burning calories is a main function of metabolism, so aerobic exercise provokes a temporarily harder-working metabolism. “More movement during the day equals higher energy expenditure and more calories burned,” Pelitera says.

2. Other Forms of Exercise Can Build Muscle

Strength training, high-intensity interval training (HIIT), and resistance training are excellent muscle-building workouts, and muscle mass also impacts metabolic rate, per the Mayo Clinic. “Muscle cells burn more calories than fat cells, even when resting, so having more muscle mass will ultimately speed up your metabolism,” Dr. Smith explains.

3. Exercise May Change How Your Body Uses Fat

When you’re active, your body releases certain hormones that help break down stored fat and use it for energy, Dr. Smith explains. Over time, regular exercise trains your body to switch more easily between using sugar and fat for fuel, depending on what it needs. “That can help with weight control and improve your overall metabolism,” he says.

How Long Does Exercise Increase Metabolism For?

We know exercise can support a faster metabolic rate in the short term, especially during and immediately after a workout. But the long-term effects are a little less clear. “There are some claims that your metabolism can be faster for up to a full day after intense exercise, but there is no one-size-fits-all window that everyone’s metabolism will be increased after working out,” Dr. Smith warns.

In scientific terms, your metabolic “afterburn” is known as EPOC, short for excess post-exercise oxygen consumption. This refers to the amount of oxygen your body needs to get back to a resting state. A study from 2011 found that exercising vigorously for 45 minutes could lead to higher EPOC for the next 14 hours, but this study was small and only included male participants. An older study suggested the effect could last up to 38 hours.

Meanwhile, the National Library of Medicine says that about an hour after your workout ends, your metabolism will essentially return to its regular rate. 

Clearly, more research is needed to understand the complex ways exercise impacts your metabolic rate in the long term. 

Can All Types of Exercise Increase Metabolism?

There’s a lot we still don’t know about the relationship between exercise and metabolism, and more research on this subject is needed. But experts believe that a few types of workouts may be more metabolism-boosting than others, at least in the short term. That includes those that build muscle and/or get your heart rate up, such as:

Some research also suggests that exercise intensity plays an important role. One older study, for example, suggests that participants’ EPOC was more prolonged and substantial after doing hard versus moderate-intensity resistance workouts. 

There is an important caveat to all this, though: “I often find that people are under the impression that we can control metabolism much more than we actually [can],” Pelitera says, pointing out that most of our caloric needs change on a day-to-day basis.

And remember: There are plenty of reasons to do these workouts that have nothing to do with metabolism at all. The list above also shouldn’t prevent you from doing other forms of movement (such as yoga or stretching) that may not be associated with a higher calorie burn but still support your health in other ways. “I tell my patients that they should be exercising for the health benefits like lower blood pressure, improved heart health, better mental health, and increased mobility in addition to improved metabolism,” Dr. Smith says.

The Takeaway

Exercising can have a positive impact on your metabolism to a degree. It’s true that when you get your heart rate up (such as while running, cycling, or swimming), your body’s metabolic rate speeds up too. And building muscle through strength workouts can also slightly boost metabolism. But research suggests that these effects don’t continue for a significant amount of time after you stop exercising. What’s more, metabolism is a complex subject, and it far from defines your overall health. “I tell my patients that rather than focusing too much on metabolism alone, think of it as just one piece of your health picture,” Dr. Smith says.